This vedio is about a coffee shop signed that "liked" them from facebook and got a free coffee, and then they could found customers private informations on the facebook and wrote down on the coffee cups.
From this, it told us that some people likes to post or show their private imformations on the facebook or some other chatting applications. The advantage is that, if people meet new friends or wants to find some one who have the same interest like themselves, they may know each other in a quick way, and become new friends.
But the bad thing is that, this may also reveal some privite secrets to strangers, like home adress, even the place for work. Some people can use this to constitute a crime, they may get some one's adress and then steal things.
The coffee shop in the video was just wanted to do a servey to tell people, if they can, don't put all of the private information on line, there is advantage and there is also disadvantage.
